Dynamic user control loses data while switching between views in multiview - asp.net

Question

I have a MultiView with two views (first one with form and second one to review data entered in first view). First view contains a TextBox and a PlaceHolder. The PlaceHolder is used to hold dynamically added add UserControl. UserControl contains DropDownList(s), TextBox, and CheckBox.
Working fine: Currently I can add new user control in the page through a Add button, which causes the page to PostBack but I do not lose any data in existing dynamic UserControl.
Issue: When I toggle between the views (using SetActiveView), I lose data in dynamically added user control but the data in the static TextBox remains intact.
Following I have the code snippet.
<%# Page Title="" Language="C#" MasterPageFile="~/M.master" AutoEventWireup="true" CodeFile="test.aspx.cs" Inherits="test" %>
<%# Reference Control="dynamic_uc.ascx" %>
<%# Register src="dynamic_uc.ascx" tagname="ucrange" tagprefix="uc1" %>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
<div class="light_blue_background pad10 helvetica innerpad5">
<asp:MultiView ID="mv_main" runat="server" ActiveViewIndex="0">
<asp:View ID="vu_add" runat="server">
<table>
<tr style="border-bottom: 1px solid #ccc;">
<td>
Name:
</td>
<td>
<asp:TextBox ID="txt_Name" runat="server" Columns="50" MaxLength="35" />
</td>
</tr>
</table>
<asp:Panel ID="pnl_TempRange_" runat="server">
</asp:Panel>
<asp:PlaceHolder ID="pl_Range" runat="server"></asp:PlaceHolder>
</asp:View>
<asp:View ID="vu_review" runat="server">
review your data
</asp:View>
</asp:MultiView>
<asp:Button ID="btn_addRange" runat="server" Text="Add Range"
CausesValidation="False" onclick="btn_addRange_Click" />
<asp:Button ID="btn_submit" runat="server" Text="Submit"
onclick="btn_submit_Click" />
<asp:Button ID="btn_modify" runat="server" Text="Modify"
onclick="btn_modify_Click" Visible="false"/>
</div>
</asp:Content>
C# Code:
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;
public partial class Test : System.Web.UI.Page
{
private static int ControlCount=0;
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
ControlCount = 0;
}
AddControls();
foreach (Control c in pnl_TempRange.Controls)
{
DropDownList ddl_UpLimit = (DropDownList)c.FindControl("ddl_Uplimit");
PopulateDropdownRange(ddl_UpLimit, 0, 100);
DropDownList ddl_LowLimit = (DropDownList)c.FindControl("ddl_Lowlimit");
PopulateDropdownRange(ddl_LowLimit, 0, 100);
}
Response.Write(tests);
}
public static Control GetPostBackControl(Page page)
{
Control control = null;
string ctrlname = page.Request.Params.Get("__EVENTTARGET");
if (ctrlname != null && ctrlname != string.Empty)
{
control = page.FindControl(ctrlname);
}
else
{
foreach (string ctl in page.Request.Form)
{
Control c = page.FindControl(ctl);
if (c is System.Web.UI.WebControls.Button)
{
control = c;
break;
}
}
}
return control;
}
private void AddControls()
{
int ID = 0;
Control cd = GetPostBackControl(Page);
if ((c != null))
{
if (c.ID.ToString() == "btn_addRange")
{
dynamic_uc++;
}
}
pl_Range.Controls.Clear();
for (int i = 0; i <= tempControlCount; i++)
{
Range DynamicUserControl = (Range)Page.LoadControl("dynamic_uc.ascx");
while (IsInDeletedLog("uc" + ID) == true)
{
ID += 1;
}
DynamicUserControl.ID = "dyn_uc" + ID;
DynamicUserControl.RemoveTempControl += this.HandleRemoveTempRange;
pl_Range.Controls.Add(DynamicUserControl);
ID += 1;
}
}
protected void btn_addRange_Click(object sender, EventArgs e)
{
}
private void PopulateDropdownRange(DropDownList ddl, int rangeMin, int rangeMax)
{
ddl.Items.Clear();
ddl.Items.Add("--Select--");
for (int i = rangeMin; i <= rangeMax; i++)
{
ddl.Items.Add(new ListItem(i.ToString(),i.ToString()));
}
}
private void BindDDl(DropDownList ddl,string strQuery)
{
ddl.DataSource = GetDataFromQuery(strQuery);
ddl.DataValueField = "VALUE";
ddl.DataTextField = "NAME";
ddl.DataBind();
ddl.Items.Insert(0,"--Select--");
}
protected void btn_submit_Click(object sender, EventArgs e)
{
if (Page.IsValid)
{
mv_main.SetActiveView(vu_reviewCmpd);
btn_submitCompound.Visible = false;
btn_confirmCompound.Visible = true;
btn_modifyCompound.Visible = true;
}
}
protected void btn_modify_Click(object sender, EventArgs e)
{
mv_main.SetActiveView(vu_add);
btn_submit.Visible = true;
btn_confirm.Visible = false;
btn_modify.Visible = false;
}
Thanks for the help.